Choragus exsertus, Poinar & Legalov, 2016

Poinar, George & Legalov, Andrei A., 2016, New Anthribidae (Coleoptera: Curculionoidea) in Dominican and Mexican ambers, Palaeontologia Electronica 148 (1), pp. 1-38 : 26-28

Choragus exsertus sp. nov.

Figure 15

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Holotype. Deposited in the PACO (accession # C-90).

Paratypes. Deposited in the PACO (accession # C-87 and C-98) and ISEA DA 2013 /1.

Description. Length body, 1.8–2.0 mm; length rostrum, 0.3–0.4 mm. Body black with covering of dark, dense, appressed setae. Rostrum wide, 0.4– 0.5 times as long as pronotum, flattened, without dorsal median carina; antennal scrobes foveiform, dorsal; forehead wide, flat, densely punctate; eyes elongate-oval, 0.9 times longer than wide, not emarginate, large, distinctly convex, upper ends closer than lower edges; vertex weakly convex, densely punctate; temples 0.4–1.2 times as long as length of eye; antennae inserted dorsally at base of rostrum, elongate, reaching transversal prosternal carina; first antennomere (scape) 3.7 times longer than wide; funicle with second to eighth antennomeres elongate-conical; second antennomere 2.4–3.1 times longer than wide, equal in length and 1.5 times as wide as first antennomere; third antennomere 2.7 times longer than wide, 0.4 times as long as and 0.4 times as narrow as second antennomere; fourth antennomere 2.0 times longer than wide, 0.8 times as long as and 1.0 times as wide as third antennomere; fifth antennomere 1.7 times longer than wide, 0.8 times as long as and 1.0 times as narrow as fourth antennomere; sixth antennomere 1.7 times longer than wide, 1.0 times as long as and 1.0 times as narrow as fifth antennomere; seventh antennomere 3.0 times longer than wide, 1.4 times as long as and 1.0 times as wide as sixth antennomere; eighth antennomere 2.7 times longer than wide, 1.1 times as long as and 1.0 times as narrow as seventh antennomere; club not compact, wider than funicle, 0.3 times as long as funicle; first antennomere of club 2.0–2.4 times longer than wide, 1.5 times as long as and 2.0 times as wide as eighth antennomere; second antennomere of club 2.3–2.7 times longer than wide, 1.3 times as long as and 1.2 times as wide as first antennomere of club; third antennomere of club 3.0–3.3 times longer than wide, 0.4–1.1 times as long as and 1.0–1.1 times as wide as second antennomere of club. Pronotum wide-bell-shaped; 1.0–1.3 times longer than wide at apex, 0.6–0.9 times longer than wide in middle and 0.7–0.8 times longer than wide at base, with lateral carinae; disk weakly convex, densely punctate, transverse dorsal pronotal carina basal; scutellum wide-trapezoidal. Elytra convex, 0.9–1.0 times longer than wide at base, 0.9 times longer than wide in middle, 0.8–1.6 times longer than wide at apical fourth, 1.4–1.5 times as long as pronotum; greatest width in middle; without clusters of setae; humeri weakly convex; striae regular and thin; strial punctures small, rounded, dense; elytral intervals flattened, quite narrow, 1.3–4.0 times as wide as striae, sparsely and gentle punctate; apices of elytra not rounded; pygidium not concealed. Thorax densely punctate; precoxal portion of prosternum long, 1.6 times as long as length of procoxal cavity, 4.0 times as long as postcoxal portion; postcoxal portion short, 0.4 times as long as length of procoxal cavity; procoxal cavities narrowly separated; mesocoxal cavities widely separated, metanepisternum narrow, 5.0–6.4 times longer than wide in middle. Abdomen convex; first ventrite 0.7–1.1 times as long as length of metacoxal cavities; second ventrite 0.8–1.1 times as long as length of first ventrite; third ventrite 0.7–1.0 times as long as length of second ventrite; fourth ventrite 1.0 times as long as length of third ventrite; fifth ventrite 1.3–1.9 times as long as length of fourth ventrite. Legs long; pro- and mesocoxae round; metacoxae transverse, almost reaching elytral margin; femora clavate, without teeth; trochanters obconical; profemora 2.9–3.3 times longer than wide; mesofemora 4.3 times longer than wide; metafemora 2.7–3.3 times longer than wide; tibiae almost straight; protibiae 6.0–7.4 times longer than wide in middle; mesotibiae 4.9 times longer than wide in middle; metatibiae 5.3–6.0 times longer than wide in middle; tarsi long; first to third tarsomeres conical; second tarsomere embracing third tarsomere laterally; fifth elongate; tarsomeres with pulvilli on underside; tarsal claws free, large, diverging, with basal teeth; protarsi: first tarsomere 1.4–1.7 times longer than wide at base; second tarsomere 0.9–1.1 times longer than wide, 0.6–0.9 times as long as and 1.2 times as wide as first tarsomere; third tarsomere subequal in length and width, 0.5 times as long as and 0.4 times as wide as second tarsomere; fifth tarsomere 2.4–3.5 times longer than wide at base, 0.9–1.0 times as long as and 0.5–0.8 times as wide as second tarsomere; metatarsi: first tarsomere 2.8 times longer than wide at base; second tarsomere 1.6 times longer than wide, 0.5–0.7 times as long as and 1.3 times as wide as first tarsomere; third tarsomere equal in length and width, 0.4 times as long as and 0.6 times as wide as second tarsomere; fifth tarsomere 4.0 times longer than wide at base, 1.0 times as long as and 0.4 times as wide as second tarsomere.

Type locality. Amber mine in the Cordillera Septentrional of the northern portion of the Dominican Republic.

Etymology. The specific epithet is taken from the Latin “exsertus ” equals protruding, in reference to the protruding eyes.

Comparison. This species is similar to Ch. major Valentine, 1999 from the USA but differs by the smaller body size, broader body, and flattened elytral intervals.

Remarks. The new species is assigned to the tribe Araecerini based on the basal transverse pronotal carina, elongate-oval eyes with the upper edges closer than lower edges, and the elongate-transverse metacoxae that almost reach the elytral margin. Placement in the genus Choragus is based on the antennae with 11 antennomeres and the antennal club being wider than the funicle.

Figures

FIGURE 15. Holotype of Choragus exsertus sp. nov. PACO no. C-90 in Dominican amber. 1, dorsal view, scale bar equals 0.3 mm; 2, ventral view, scale bar equals 0.4 mm; and 3, lateral view, scale bar equals 0.4 mm.